Universal hinged treads for folding attic stairs
US7578371B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Oct 28, 2005 |
| Grant date | Aug 25, 2009 |
| Priority date | — |
| Expiry date | Aug 7, 2026 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE04F11/064
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A universal hinged tread system includes a folding stair set with one or more primary treads. At least one auxiliary tread is hingedly attached atop at least one primary tread. The folding stair set includes at least two hingedly attached sections. The hingedly attached sections fold flat against each other when in a stowed position, and every other folding stair section is inverted when in the stowed position. Each auxiliary tread is angularly displaced from its primary tread as its folding stair section is inverted. The auxiliary treads do not obstruct any primary treads on other sections when in a stowed position. The auxiliary treads include a beveled lower front edge to aid the auxiliary treads in deflecting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.